Air-back for stokers



M. ALPERN. AIR BACK FOR STOKERS.

APPLICAT ED NOV-2. 1 916- Patented June15, 1920.

4 SHEETS-SHEET I.

M. ALPERN. AIR BACK FOR STOKERS. APPLICATION FILED NOV. 2. I916.

' Patented June 15, 1920.

4 $HEETS-SHEET 2- M. ALPERN. AIR BACK FOR STOKERS. APPLICATION FILEDNOV. 2, 1916.

Patented June 15, 1920.

4 SHEETS-SHEET .3.

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M. ALPERN. AIR BACK FOR STOKERS. APPLICATION FILED NOV.2, 1916.

Patented J une 15, 1920.

4 SHEETS-SHEET 4- 1/1/11 ll/l/Il/ /fl/l/I 91/11/14 wan p nqya W UNITEDSTATES PATENT OFFICE.

MAXWELL ALPERN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO AMERICANENGINEERING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

AIR-BACK FOR STOKERS.

Specification of Letters Patent.

Patented June 15,1920.

Application filed November 2, 1916. Serial No. 129,170.

over and cool certain structures facing or covering at least one wall ofsuch ash pocket.

I further desire to provide a novel form of air back for apparatus ofthe class noted, so arranged as to utilize the air in cooling the ashesand clinkers in the ash pocket, as well as for aiding in the combustionof any unburnt fuel which may be mixed with or delivered to the top partof the ashes in said pocket.

A further object of the invention is to provide a novel form of aircooled lining for an ash pocket or facing for a bridge wall which shallbe of such construction as to minimize the likelihood of injury byreason of expansion and contraction, and which shall be so disposed asto materially increase the operating and thermal efficiency of theapparatus with which it is employed.

These objects and other advantageous ends I secure as hereinafter setforth, reference being had to the accompanying drawings, in which,

Figure 1 is a vertical section illustrating a boiler equipped with myinvention;

Fig. 2 is a vertical section on an enlarged scale illustrating myinvention as applied to a furnace similar to that shown in Fig. 1;

Fig. 3 is a horizontal section on the line 3--3, Fig. 2;

Figs. 4 and 5 are respectively front and side elevations of one of theair back sections; 1

Figs. 6 and 7 are vertical sections taken on the lines 6-6 and 7-7, Fig.4;

Figs. 8 and 9 are transverse sections on the lines 8-8 and 9-9, Fig. 7;and

Fig. 10 is an end elevation ofthe structure shown in Fi 4.

In the above drawings, 1 represents the its lower portion angularlyadjustable ash confining plates 6 and provided at its bottom with an ashcrushing and discharging mem her 7 consisting of a rotary structurehaving projecting blades or teeth. The ashes crushed by and dischargedbetween the rotary structure and the lower portions of the plates 6 fallinto a sealed ash pit 8.

According to the present invention there is set in that portion of thebridge wall 2 which forms one side of the ash pocket 5, a series ofvertically corrugated facing sections 9 held in place, and so arrangedthat their lower ends are removably bolted as shown in Fig. 2, to atransversely extending member 10 mounted in the bridge wall, while theirupper ends are provided with a pair of projecting lugs or fingers l1projecting back of a second transversely extending end of each sectionhas perforations 14:

formed in the outer parts of its corrugations and in addition the lowerends of the sections are spaced away from the adjacent part of thebridge wall structure so that air flowing vertically downward throughsaid corrugations can to some extent escape through the perforations 14,although the greater portion is free to pass out of the lower ends ofthe corrugations and into the ash pocket through this space or opening15.

For supplying air to the air back formed by these corrugated sections, Iprovide in the bridge wall a passage 17 extending transversely of thestoker and connected through a suitable passage 18 to an air conduit 19sup lied with air from the air conduit 20 ordinarily delivering to thewind box 21 of the stoker. In Fig. l, I have shown the constructionadopted when both the air back and the wind box supply conduit are fedfrom a common source, the passage 17 in the bridge Wall 2 beingconnected by a conduit 18 with a transversely extending trunk or airreservoir 19 connected by a conduit 19 to the wind box supply conduit20".

With the above described arrangement of parts the air delivered to thetransversely extending passage 17 flows into the upper ends of thecorrugated sections constituting the air back, and passes down throughthese latter to their lower ends where it escapes through the openings14; and 15 into the lower part of the ash receiving pocket im mediatelyadjacent the discharge apparatus thereof. This air thus not only coolsthe air back sections 9 so as toprevent the adhering of ashesandclinkers thereto, but acts to cool the ashes in the pocket, beingnecessarily required to flow upwardly through the latter in view of thefact that the ash pit is sealed or air tight.

In thus flowing, the air is heated and insures the complete combustionof any unburnt materialwhich may be present among the ashes. Moreoverwith the above described arrangement, the stoker mechanism may be sooperated that unburnt fuel is delivered on top of the ashes in the upperpart of the ash pocket and this likewise may be economically burnt withthe highly heated air flowing upwardly through it.

As will be understood by those skilled in the art, the ashesaccumulating in the pocket are continuously or intermittently dischargedinto the ash pit by the rotation of the crushingor discharging member 7,which may obviously be operated at a higher speed than has hitherto beenpermissible since such ashes are cooled in a comparatively short a time.

In that form of the invention shown in Fig. 1, I have illustratedguiding structures 25 mounted in the ash pocket below and incontinuation of the air back sections 9, for

the purpose of positively directing the down wardly moving body of ashesand clinkers toward and into engagement with the rotary dischargingdevice 7.

I claim:

1. The combination in an inclined, underfeed stoker of a furnaceincluding two structures defining an elongated, horizontally extendingash pocket; means for discharging ashes from said pocket; a corrugatedplate mounted on one of said structures; and means for delivering airunder pressure to the rear face of said plate.

2. The combination in an inclined, underfeed stoker of a furnaceincluding two structures defining an elongated, horizontally extendingash pocket; means for discharging ashes from said pocket; with acorrugated plate mounted on one of said structures and having air spacesadjacent its rear face.

3. The combination of an inclined underfeed stoker; a bridge wallcooperating therewith to form a transversely extending ash pocket; meansfor discharging ashes from said pocket; a sectional verticallycorrugated plate having the sections removably mounted 011 said bridgewall within the pocket; and means for delivering air under pressure tothe rear face of the plate.

4;. The combination of an inclined underfeed stoker; a bridge wallcooperating therewith to form a transversely extending ash pocket; meansfor discharging ashes from said pocket; a sectional verticallycorrugated plate having its sections mounted on said bridge wall withinthe pocket; and means for delivering air under pressure to the rear faceof the plate, there being openings through the lower portion of theplate for delivering air into the ash pocket.

5. The combination in a furnace of a stoker; a bridge wall cooperatingtherewith to form an ash pocket; means for discharging ashes from -saidpocket; a plate mounted on said bridge wall within the pocket; means forsupplying air under pressure to cool said plate; with a guide platemounted between the ash discharging means and the lower toward said ashdischarging means.

MAXWELL ALPERN.

